V

VA

Vac

Variable Resistor

Varistor

Combination of Variable Resistor. A two-electrode semiconductor device having a non-linear, voltage-dependent resistance (usually a high resistance at low voltages and low resistance at high voltages). Often used to protect circuits against transient voltages.

Schematic Symbol for a Varistor

Varnish Dip

The process of dipping a transformer or coil in varnish to bind or protect materials.

Vcc

Voltage Collector Collector. Positive supply voltage of a Bipolar Junction Transistor. The doubled suffix indicates that the voltage is common. i.e. it is the supply voltage to one (or more) collectors and not just the voltage at a specific collector.

Vdc

Vdd

Voltage Drain Drain. Positive supply voltage of a Field Effect Transistor. The doubled suffix indicates that the voltage is common. i.e. it is the supply voltage to one (or more) drains and not just the voltage at a specific drain.

VDE

VDR

Vee

Voltage Emitter Emitter. Negative supply voltage of a Bipolar Junction Transistor. The doubled suffix indicates that the voltage is common. i.e. it is the supply voltage to one (or more) emitters and not just the voltage at a specific emitter.

Verband Deutscher Elektrotechniker (VDE)

Vias

Volt (V)

Unit of measurement of electromotive force or potential difference. Symbol E, in electricity; symbol V in semiconductor circuits. A current of 1 A passing through a resistance of 1 ohm will produce a potential difference of 1 volt. See Ohm's Law. Written as 'volt'. Abbreviated to V.

Volt Microsecond / Volts per Microsecond

Rate of change of voltage over a period of time expressed in volts/microseconds.

Volt Second

In a control circuit, the on-time x the voltage applied to the winding is controlled (effectively running the magnetic component at peak magnetic flux density).

Volt Second Clamp

A circuit in the control of the pulse width modulator located in the primary which terminates the pulse when the volt seconds applied to the primary of the transformer exceeds a predetermined value.

Voltage

A derivative electrical quantity, E, measured in the units volts and defined in terms of the independently obtained ampere, I, and the unit or Resistance, ohm (R) by Ohm’s Law E=IR.

Voltage Balance

The difference in magnitude, in percent, between differential tracking output voltages of a power supply (PSU) where the voltages have equal nominal values with opposite polarities.

Voltage Source

Voltage Stabilisation

Volt-Ampere (VA)

Vss

Voltage Source Source. Negative supply voltage of a Field Effect Transistor. The doubled suffix indicates that the voltage is common. i.e. it is the supply voltage to one (or more) sources and not just the voltage at a specific source.